Heat exchanger



2 Sheets-Sheet 1 ATTORNEY R. M. SWARTZ ET AL HEAT EXCHANGER Filed Dec.51. 1931 Nov. 14, 1933.

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HEAT EXQHANGER Filed Dec. 31, 1931 2 Sheets-Sheet 2 ATTORNEY PatentedNov. 14, 1933 UNITED STATES HEAT EXCHANGEB Ralph M. Sta... Bogota, N.1., and Carl s. Reed, New York, N. Y.; said Swartz assignor to TheSuperheater Company, New York, N. Y.

Application December 31, 1931 Serial No. 584,238

14 Claims.

Our invention relates to the art of heat exchange and aims to provide aheat exchanger adapted to handle liquid at high pressures.

In the oil industry it has become common to utilize heat exchangers torecuperate latent heat in vapors given oif from cracking and distillingchambers by cooling such vapors with liquid moving toward the crackingor distilling chambers. Such liquid is often under high pressure,

especially in installations of the cracking type, while it is essentialto provide clean-out joints at the ends of the tubular elements in whichthe liquid is .heated in order to maintain their thermal efficiency.Such clean-out joints are usually of expensive design because the heatexchangers are often placed in high pressure lines and the joints mustbe tight against hot oil to prevent danger of fire. Moreover, ashut-down involves heavy expense for each hour the plant I is out ofoperation.

It is an object of our invention to provide a design adapted to minimizethe cost of high pressure heat exchangers and. the length of a shutdownfor cleaning a heat exchanger.

The novel features of our invention are point-- ed out in the appendedclaims. The invention itself, together with its object and advantages,

will best be understood, however, from a detailed description of anapparatus in accordance with the invention, and such a description willnow be given in connection with the accompanying drawings of a heatexchanger selected by way of example from a number of possibleemb'odiments of the invention.

In-the drawings Fig. Us a central longitudinal section of a heatexchanger in accordance with the invention.

Fig. 2 is a section on line 2-2 of Fig. 1 looking in the direction ofthe arrows.

Fig. 3 is a section on the line 3-3 of Fig. 1 looking in the directionof the arrows.

The apparatus illustrated in the drawings comprises an outer shell 10having a ring 12 at one end thereof and a portion 14 connected to ring45 12 by a readily disconnectable joint 16. Vapors for heating areintroduced into shell 10 through inlet 18 in ring 12 and discharged fromthe shell through outlet 20, also in such ring. Supported within shell10 is a group 22 of tubular units 24, 24 through which the liquid to beheated is passed. Each of the units 24 is of serpentine form lying in asubstantially given plane, the units 24 of group 22 all having theirplanes arranged substantially parallel. Owing to their serpentine 55form, units 24 have considerable flexibility to accommodate expansionsand contractions due to changes in temperature. Along one side of eachunit 24 is a row of retiu'n bends 26, 26 connecting straight pipelengths or runs of the units. 00 In the arrangement illustrated, shell10 is ar ranged'with its axis vertlcaland the bends 26 at the uppersides of units 24. This fact is utilized in the arrangement shown toprovide means for lifting the group 22 as a whole or unit so that it canbe quickly taken from the exchanger and a clean group put in its placewhenever it is necessary to clean the group of units. The time duringwhich it is necessary to shut down the plant to clean the heat exchangeris thereby reduced to a minimum. As illustrated for this purpose, eachbend 26 has fixed thereto an upward extension 28. The upper end of eachsuch extension is threaded to receive a nut 30 whereby bar 32, shown asan angle, may be secured to each unit 24. The bars 32 are all connectedtogether into a framework by cross bars 34, 34, also shown as angles,and the frame so provided has lifting eyes 36, 36 therein by which thewhole group 22 may be hoisted as a unit from the ring 12 when the jointsof the fluid connections for the units have been broken. The portion 14of the shell also has eye members 38, 38 fixed thereto whereby it may belifted from ring 12 when the joint 16 has been broken.

The units 24 have jointed connections at their ends with header blocks40, 40. Preferably the joints between units 24 and blocks 40 are of theground'cone type illustrated at 42. However,-we do not limit ourselvesto this. It will be understood that the ends of units 24 are clamped toblocks 40 by suitable means, not shown, which are well understood andcommonly used in connection with such joints. The blocks 40, and therebythe group 22, are supported when. in use on supporting brackets 44, 44of triangular form in plan which are fixed to the inner face of ring 12.The upper triangular faces of the brackets 44 are shown as contactingwith the under faces of the headers 40. Brackets 44 extend beyond oneedge of ring 12 so that the undersides of blocks 40 are readilyaccessible wheneverportion 14 has been removed from 12. The utility ofthis feature will appear hereinbelow.

Liquid to be heated in units 24 is introduced into the shell 10 throughheavy blocks 50, 50 which extend through the wall of ring 12. Blocks 50are shown as welded into ring 12 as indicated at 52 so that there shallnot be any leakage through the shellaround the edges of the blocks.Passageways 54, 54 are provided through blocks 50 for inlet and outletrespectively of liquid to be heated. Suitable means, not shown, may beused for connecting pipes for liquid at the ends of the passageways 54outside the shell 10. At the ends of passageways 54 within shell .10,means-shown at 5'6, 56, (Fig. 2) are provided for making a liquid tightjoint between the blocks 50 and tubular connections 58, 53 for liquid,one of which extends from each block 50 to a joint on the under side ofone of the header blocks40. As illustrated,

each connection 58 extends within ring 12 around beneath the lower endof group 22 for a material part of 360 deg. and the blocks 40 are placedsome distance above the blocks 50 so that the connections 58 can curveup gradually from one set of blocks to the other. The connections 58thereby have suflicient flexibility to readily accommodate themselves toexpansions and contractions of the various parts due to changes intemperature. The connections 58 and blocks 50 are expected usually toremain in place whereas the joints 60 between the upper ends ofconnections 58 and the blocks 40 will be broken whenever it is desiredto remove a group 22 from the ring 12. Joints 60 are so designed thatthey may be readily broken and reassembled without danger of causingleakage. We have illustrated joints 60, however, as of a well known typeas we do not limit ourselves to any particular form of joint. Whilethere is seldom need to disturb the joints between blocks 50 andconnections 58, such joints are preferably like joinrts 60 and are soplaced that connections 58 may be readily removed when desired. From thejoints 60 connections are made between the tubes 58 and the elements 24through the blocks 40 by passages 62 and 64 within such blocks.

It will be seen that the group 22 of tubular elements has a rectangular,preferably a square cross-section. See Figs. 2 and 3. It is preferred,however, that the shell 10 be circular. The vacant segments between theinner surface of shell 10 and the group 22 must therefore be filled into prevent much of the heating fluid from passing through the shellwithout contacting with units 24. For this purpose we have shown flatlongitudinally extending plates 65, 65 along the sides of the group 22,two of the edges of each plate 65 being joined to portion 14 of theshell along rectilinear elements thereof. The segmental spaces definedby plates 65 are closed at one end, or both ends, to prevent passage ofgases therethru, transverse plates 65a, 65a preferably being used forthis purpose at the upperends of plates 65. At their lower ends, plates65 are shown as bent toward the shell to provide room for the The heatmay be abstracted from the vapors or gases in either a multipass orsingle-pass arrangement in accordance with our invention. As shown, wehave provided two passes for the heating fluid within shell 10 byarranging a central bafile plate 100 extending along the central axis ofshell 10 from the closed end of ring 12 to a point near the end of group22 removed from ring 12. Plate 100 preferably extends entirely acrossthe shell 10 along the diameter thereof and cuts through the plates 65,although this feature is immaterial to the invention. The battle 100 isintended to remain in place when the group 22 is removed from ring 12and plates 65 have means, shown in the form of curved somewhat resilientlips 10,2, 102, for permitting plates 65 to slide on plate 100 and forpreventing leakage of gas from the gas passes into and out of the closedsegments at two sides of the gas passes. The portion 14 of the shell ismovable with respect to plate 100, and we prefer to employ a gas tightjoint between plate 1"! and portion 14. We have illustrated a jointbetween parts 100 and 14 of the same type as those between plate 100 andplates 65. This is a matter of convenience only. As shown, two pairs oflips 104, 104 are welded to portion 14 so as to embrace the edges ofplate 100 to prevent leakage between plate 100 and the portion 14 of theshell. Similar lips, not shown, are employed on the ring 12 for the samepurpose. The end plate 106 which closes the ring 12 is also providedwith means making a gas tight joint with plate 100. Lips 104a, 104a areillustrated for this purpose. It will be seen that the joints at theedges of plate 100 permit its ready removal from shell 10 when desiredwithout disturbing the group 22, by simply removing the end plate 106.It will be seen further that liquid connections 58 do not pass throughplate 100,.but lie one on one side of said plate and one on the other,whereby plate 100 may be removed and replaced without interfering withconnections 58. Such arrangement furthermore avoids joints in the plate100. To permit liquid to pass from one side of plate 100 to the otherwhen the heating fluid used is primarily vaporous, a trap pipe 108 isshown having its ends passing through plate 106 at points on oppositesides of plate 100.

It is preferred also to employ a perforated baflle 110 on the inlet sideof plate 100 and so arranged as to direct some of the fluid enteringthrough inlet 18 first downward so that it may enter group 22 near theend of the group and to prevent direct impact on the clean-outsmentioned hereinbelow. We prefer further to employ means to ensure theportion 14 of shell 10 shall fit together without difiiculty when theseparts are being assembled. For such purpose we have illustrated a heavypin 111 fixed to the centre of the closed end of portion 14 and adaptedto enter an aperture 112 in a block 114 fixed to group 22 so that theportion 14 will be held in proper position to make a tight joint withring 12 as the parts are brought together. The outer portion of aperture112 is beveled as shown at 116 to facilitate entry of the pin 111 intoaperture 112. As illustrated, block 114 is fixed to flanges 118 on twoof the cross-bars 34 at one end of group 22.

At one side of each of units 24 there is shown a row of return bends 66,66 each of which has a tubular clean-out 68 extending therefrom andhaving a closure fitting 70 thereon of known type. Each of the fittings70 includes a plug member, not shown, which may be readily removed whenit is desired to clean out the pipe runs of the units.

The clean-outs are shown at the bottoms of units 24, but we do not limitourselves to this. Also, clean-outs may be placed along both sides ofunits 24, if desired.

It will be seen that an exchanger in accordance with our inventionavoids the necessity of rolling joints into heavy tube sheets therebyreducing the expense of manufacture, while the parts are so designed asto permit them to expand and contract with the changes of temperaturewithout serious internal stresses or danger of loosening the joints tocause leakage. Our heat exchanger may, moreover, be readily disassembledby merely breaking the joint 16 in the shell and the two joints 60, itbeing thereupon easy to remove a group of heating units and substituteanother in a minimum of time.

While we have described our novel heat exchanger as applied to heatingoil for distilling and cracking installations, we do not limit ourselvesto any particular field of use for our invention.

While we have illustrated and described above in detail an apparatushaving only a single baflle within the tube bank 22, it is evident thatwe may use as many such bailies as necessary to provide the desirednumber of passes for the gases provided only there is one row of tuberuns in each pass.

Furthermore, in order to satisfy the best purposes of any particulardesign the two fluid mediums may be arranged in parallel flow, counterflow, cross flow or a combination thereof.

What we claim, is:

1. A heat exchanger having a shell composed of a ring and a portionreleasably connected thereto, said ring having vapor inlet and outletopenings and means forming liquid inlet and outlet openingstherethrough, a group of tubular units within'said shell, a support forsaid group carried on'said ring, connections for conducting liquidbetween said liquid inlet and outlet and said units, and means formingreadily separable joints between said connections and said units.

2. A heat exchanger having a shell including a ring at one end thereofand a portion readily separable therefrom, said ring having vapor inletand outlet openings therethrough, a set of tubular heating units withinsaid shell, a support for said units on said ring, liquid inlet andoutlet connections for said units extending through said ring, meanswhereby said connections may be readily disconnected from said units,and means whereby said units may be removed simultaneously when saidportion has been removed from said ring.

3. A heat exchanger having a group of tubular units therein for liquidto be heated, said units,

each having a bend at two opposite sides, projections fixed to the bendsat one side of said units, and a frame tying said projections togetherwhereby said group may be lifted as a whole.

r. A heat exchanger as set forth in claim 3 and in which the bends ofthe units at their side opposite the lifting frame have tubularclean-out extensions thereon.

5. A heat exchanger having a cylindrical shell provided near one endwith an inlet and an outlet for heating vapors, a group of tubular unitsin said shell and havinga rectangular outline in cross-section, bafflesalong opposite sides of said group, and a third baflle arrangedcentrally of said group and extending from the end of the shell havingsaid inlet and said outlet away therefrom to a point not so close to theother end of said shell as said two side baiiies.

6. A heat exchanger having a shell including a ring at one end thereofand a portion readily separable from said ring, a group of units withinsaid shell for liquid to be heated, said ring having a vapor inlet andoutlet therein and blocks extending therethrough and providing an inletand outlet for liquid for said units, header blocks for said unitswithin and unconnected with said shell, and liquid connections betweensaid first blocks and said header blocks and having means forming areadily disconnected joint between themselves and the headers.

7. A heat exchanger as set forth in claim 6 I and in which the liquidconnections both curve and extend longitudinally whereby expansion andcontraction of the parts is accommodated.

8. A heat exchanger as set forth in claim 6 and in which brackets forsupporting the group of units are fixed to the inner face of the ringand extend laterally therefrom to contact with the headers for the unitsand thereby support the 9. A heat exchanger as set forth in claim 6 andin which the liquid connections lie at one end of the group of unitstogether with, a baflie extending centrally of the group of units fromthe end of the shell having the ring nearly to openings of which saidinlet is in said ring, said ring also. having liquid inlet and outletopenings therein, a group of tubular units within said shell, said groupand said ring being arranged so that the units are supported from thering, means for conducting liquid located between said liquid inlet'andoutlet and said units and means forming readily separable joints betweensaid first means and said units.

11. A heat exchanger having a shell including a base ring and a portionreleasably connected thereto, said ring having a vapor passage thereinand having also apertures for the inlet and discharge of liquid, a pairof headers, one arranged to receive liquid thru said inlet aperture andone to discharge liquid thru said discharge aperture, means forsupporting said headers from said ring, a plurality of serpentine unitssupported from said ring and extending upwardly into said releasableportion of the shell, said units having each a return bend at top and atbottom, said bottom bend having a clean-out associated therewith, andmeans forming readily separable joints between said headers and saidunits.

12. A heat exchanger having a group of serpentine tubular units therein,said units having each a plurality of bends at its top and at itsbottom, projections fixed to the bends at the tops of the units, saidbends at .the bottoms of said units having cleanout means associatedtherewith, and a frame tying said projections together whereby saidunits may be' lifted as a unit.

13. A heat exchanger having a pair of parallel header chambers in thelower part thereof a group of serpentine tubular units each having oneend removably supported by and connected to receive fluid from one ofsaid chambers and its other end supported by and connected to deliverfluid to the other of said chambers, said units each having a pluralityof substantially vertical sections connected by return bends andunsupported except by the ends of the units, and means tying togetherthe group of bends of each unit which lies the farther from saidchambers.

14. A heat exchanger having a casing provided with an inlet passage andan outlet passage for one fluid, a pair of spaced headers near one endthereof having connections for a different fluid,

